CN111656613A

CN111656613A - Antenna device, vehicle window glass, and window glass structure

Info

Publication number: CN111656613A
Application number: CN201980010727.9A
Authority: CN
Inventors: 东海林英明; 竹内彰一
Original assignee: Asahi Glass Co Ltd
Current assignee: AGC Inc
Priority date: 2018-02-02
Filing date: 2019-01-31
Publication date: 2020-09-11
Anticipated expiration: 2039-01-31
Also published as: DE112019000636T5; US11522278B2; US20200335857A1; CN111656613B; WO2019151407A1; JP7140145B2; JPWO2019151407A1

Abstract

An antenna device according to the present invention includes a first conductive plate having a first end portion and a second end portion on the opposite side of the first end portion, a feeding portion provided between the first end portion and the second end portion; a second conductive plate having a third end connected to the feeding portion, a fourth end located at a position distant from the first conductive plate, and a plate surface whose width in a direction parallel to the first conductive plate increases from the third end toward the fourth end; the third conductive plate has a fifth end portion capacitively coupled to the fourth end portion, a sixth end portion connected to the first conductive plate on the first end portion side with respect to the feeding portion, and an opposing portion opposing the plate surface.

Description

Antenna device, vehicle window glass, and window glass structure

Technical Field

The invention relates to an antenna device, a vehicle window glass and a window glass structure.

Background

In recent years, a change has been made in the expansion of high-speed and large-capacity communication infrastructure, such as the shift from 4G LTE to 5G (sub6), and in addition to the conventional 700MHz to 3GHz band, a maximum 6GHz band is used, and the used band tends to expand. On the other hand, in the frequency band used in 4G LTE in the world, 698 to 960MHz and 1790 to 2690MHz are mainly required. Therefore, antennas capable of receiving signals in a wide frequency band from 700MHz to 6GHz are required as antennas corresponding to both 4G and 5G.

For example, as a uwb (ultra Wide band) antenna capable of receiving signals over a Wide frequency band, an antenna having a sector-shaped radiating element erected on a ground plate is known (for example, see patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2007-235395

Disclosure of Invention

Technical problem to be solved by the invention

However, the frequency at which a UWB antenna having a sector-shaped radiating element erected on a ground plate can receive a signal depends almost entirely on the length of the outer edge portion of its radiating element. Therefore, it has been difficult to further widen the frequency band of the receivable signal in the conventional technique.

The present disclosure provides an antenna device that facilitates the widening of the frequency band of a receivable signal, and a vehicle window glass and a window glass structure that include at least one of the antenna devices.

Technical scheme for solving technical problem

The present disclosure provides an antenna device, and a vehicle window glass and a window glass structure provided with at least one antenna device, wherein the antenna device is provided with a first conductor plate, a second conductor plate and a third conductor plate, the first conductor plate is provided with a first end part and a second end part on the opposite side of the first end part, and a first feeding part is arranged between the first end part and the second end part;

a second conductive plate having a third end connected to the first feeding portion, a fourth end located at a position distant from the first conductive plate, and a plate surface whose width in a direction parallel to the first conductive plate increases from the third end toward the fourth end;

the third conductive plate has a fifth end portion capacitively coupled to the fourth end portion, a sixth end portion connected to the first conductive plate on the first end portion side with respect to the first feeding portion, and an opposing portion opposing the plate surface.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, it is possible to provide an antenna device that easily achieves a wide frequency band of a frequency that can receive a signal, and a vehicle window glass and a window glass structure that include at least one of the antenna devices.

Drawings

Fig. 1 is a perspective view showing an example of the configuration of the antenna device of the present embodiment.

Fig. 2 is a diagram showing a first example of a power supply wire connected to a power supply unit.

Fig. 3 is a diagram showing a second example of the power supply wire connected to the power supply unit.

Fig. 4 is a diagram showing an example of the configuration of the matching circuit.

Fig. 5 is a diagram showing an example of the configuration of the demultiplexer.

Fig. 6 is a cross-sectional view schematically showing an example of the structure of a vehicle window glass with an antenna device.

Fig. 7 shows an example of a radiation pattern on a vertical plane in the low frequency band of the antenna device.

Fig. 8 shows an example of a radiation pattern on a horizontal plane in a low frequency band of the antenna device.

Fig. 9 shows an example of a radiation pattern on a vertical plane in the high frequency band of the antenna device.

Fig. 10 shows an example of a radiation pattern on a horizontal plane in a high frequency band of the antenna device.

Fig. 11 shows an example of the frequency characteristics of VSWR (standing wave ratio) of the antenna device.

FIG. 12 shows an example of frequency characteristics (699 to 7100MHz) of the average gain in the horizontal plane.

Fig. 13 is a perspective view showing a first modification of the configuration of the antenna device of the present embodiment.

Fig. 14 is a perspective view showing a second modification of the configuration of the antenna device of the present embodiment.

Fig. 15 is a perspective view showing a third modification of the structure of the antenna device of the present embodiment.

Fig. 16 is a perspective view showing a fourth modification of the configuration of the antenna device of the present embodiment.

Fig. 17 shows an example of the frequency characteristic of VSWR (standing wave ratio) of the antenna device according to the first modification.

Fig. 18 shows an example of a radiation pattern on a horizontal plane of the antenna device according to the first modification.

Fig. 19 is a diagram showing an example of the correlation coefficient of the antenna device according to the first modification.

Detailed Description

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In addition, in each embodiment, the directions of parallel, right-angle, orthogonal, horizontal, vertical, up-down, left-right, and the like may have variations to such an extent that the effects of the present invention are not impaired. The X-axis direction, the Y-axis direction, and the Z-axis direction respectively indicate a direction parallel to the X-axis, a direction parallel to the Y-axis, and a direction parallel to the Z-axis. The X-axis direction, the Y-axis direction and the Z-axis direction are orthogonal to each other. The antenna device and the antenna have the same meaning.

Fig. 1 is a diagram showing an example of the structure of the antenna device according to the present embodiment. The antenna device 101 shown in fig. 1 includes a conductor plate 10, a conductor plate 20, and a conductor plate 30.

The conductive plate 10 is an example of a first conductive plate. The conductive plate 10 is provided with a feeding portion 3 using the conductive plate 10 as a ground reference. The feeding unit 3 is an example of a first feeding unit, and indicates a feeding point of the antenna device 101. In the present embodiment, the conductor plate 10 has an end portion 13 and an end portion 14 on the opposite side of the end portion 13. The

end portions

13 and 14 are located away from each other in the X-axis direction. The power supply portion 3 is disposed between the

end portions

13 and 14. The conductor plate 10 has a first plate surface portion 12 extending from the feeding portion 3 toward the direction 13, and a second plate surface portion 11 extending from the feeding portion 3 toward the end portion 14.

The conductive plate 20 is an example of a second conductive plate. The conductive plate 20 has an end portion 23 connected to the feeding portion 3 and an end portion 24 located at a position distant from the conductive plate 10. The end portion 24 is located on the opposite side of the end portion 23, more specifically, on the opposite side of the end portion 23 from the side where the conductor plate 10 is present. The

end portions

23 and 24 are located away from each other in the Z-axis direction.

The conductive plate 20 has a plate surface 21, and the width of the plate surface 21 in a direction parallel to the conductive plate 10 (Y-axis direction in fig. 1) increases from the end 23 toward the end 24. Here, the direction parallel to the conductor plate 10 may be the X-axis direction, but is preferably a direction inclined in a range of less than ± 90 ° with respect to the Y-axis direction. In particular, the direction parallel to the conductive plate 10 is preferably within a range of ± 45 ° with respect to the Y-axis direction, more preferably within a range of ± 20 °, still more preferably within a range of ± 5 °, and most preferably coincides with the Y-axis direction. Note that the phrase "the conductor plate 20 expands from the end 23 toward the end 24" means that there may be a portion that expands from the end 23 toward the end 24, and there may be a portion that continues with the same width or a portion that narrows in width from the end 23 toward the end 24, for example. In addition, the conductor plate 20 preferably has no portion whose width is narrowed from the end portion 23 toward the end portion 24. Further, the conductor plate 20 may have a flat shape without being bent, but may have a three-dimensional shape with a bent portion as shown in the drawing. The conductive plate 20 in the present embodiment has a plate surface 21 including an end portion 23, and a plate surface 22 including an end portion 24. The plate surface 22 is a portion bent at the bent portion 25 with respect to the plate surface 21. By providing the curved plate surface 21, the height of the antenna device 101 can be reduced as compared with a case where the plate surface is not curved. The height reduction described here corresponds to shortening the distance (height) in the Z-axis direction from the conductive plate 10.

The conductive plate 30 is an example of a third conductive plate. The conductive plate 30 has an end portion 33 capacitively coupled to the end portion 24 of the conductive plate 20, and an end portion 34 connected to the conductive plate 10 on the side of the end portion 13 with respect to the feeding portion 3. The end portion 34 is located at a position opposite to the end portion 33. The

end portions

33 and 34 are located at positions distant from each other in the Z-axis direction and the X-axis direction. In the present embodiment, the end portion 33 is capacitively coupled to the end portion 24 through the gap 2 having a gap capable of capacitive coupling. The direction of the gap 2 for forming capacitive coupling is not limited to the X-axis direction shown in the figure, and may be the Z-axis direction or the Y-axis direction, for example, the plate surface 22 may have a shape having a curvature in the X-axis direction

The direction of the angle of (a). In addition, the capacitive coupling between the

end portions

24 and 33 may be realized by other forms such as a comb structure or a dielectric load.

In the present embodiment, the conductive plate 30 includes an opposing portion 31 that opposes the plate surface 21 of the conductive plate 20 in the X-axis direction and an opposing portion 32 that opposes the first plate surface portion 12 of the conductive plate 10 in the Z-axis direction. The opposing portion 32 is a portion bent at the bent portion 35 with respect to the opposing portion 31. The opposing portion 32 includes an end 33 and the opposing portion 31 includes an end 34.

Thus, in the antenna device 101 of the present embodiment, the conductive plate 20 is connected to the feeding portion 3 having the conductive plate 10 as a ground reference at the end portion 23, and the width of the plate surface 21 is formed to increase as it goes away from the conductive plate 10. Therefore, by setting the length of the outer edge portion (for example, a curved portion extending from the end portion 23) of the plate surface 21 so that the conductive plate 20 has an electrical length that operates in a desired frequency range, the conductive plate 20 can function as a radiation element of the UWB antenna.

On the other hand, the conductive plate 20 is connected to the feeding portion 3 having the conductive plate 10 as a ground reference at the end portion 23, and the end portion 24 of the conductive plate 20 and the end portion 33 of the conductive plate 30 are capacitively coupled. Therefore, the conductor plate 20 also functions as a power supply element for supplying power to the conductor plate 30 by capacitive coupling. Further, the conductor plate 30 is connected to the conductor plate 10 at an end 34. Therefore, the

conductive plates

10 and 30, which are formed by coupling the conductive plate 30 and the conductive plate 10 together, are excited by capacitive coupling as one radiation element (one radiation element in a J shape in the present embodiment) to which power is supplied from the conductive plate 20. Therefore, by setting the conductor lengths of the conductor plate 30 and the conductor plate 10 so that the

conductor plates

10 and 30 have an electrical length that operates in a desired frequency range, the

conductor plates

10 and 30 can function as radiation elements that operate at a different resonance frequency from the conductor plate 20.

Thus, the antenna device 101 shown in fig. 1 includes the first antenna in which the conductive plate 20 is operated not only in the first operation mode in which the conductive plate 20 is operated as the radiation element but also in the second operation mode in which the conductive plate 20 is operated as the feeding element and the

conductive plates

10 and 30 are operated as the radiation elements. That is, since the

conductive plates

10 and 30 can resonate at a resonance frequency different from the resonance frequency of the conductive plate 20, the frequency of the antenna device 101 capable of receiving a signal can be easily widened. The antenna device 101 resonates with a current ib flowing through the conductor plate 20 and a current ic flowing through the conductor plate 30 in the first operation mode, and resonates with a current ia flowing through the

conductor plates

10 and 30 in the second operation mode.

For example, the conductor plate 20 has a first electrical length Le1 that resonates at a first operating frequency f1, and the

conductor plates

10,30 have a second electrical length Le2 that resonates at a second operating frequency f2 that is lower than the first operating frequency f 1. This allows the

conductive plates

10 and 30 to resonate at a resonant frequency lower than the lowest resonant frequency of the conductive plate 20.

For example, if the first electrical length Le1 is set to a quarter wavelength of the first operating frequency f1, the conductor plate 20 can be made small and the conductor plate 20 can be resonated at the first operating frequency f 1. Further, for example, if the second electrical length Le2 is set to a quarter wavelength of the second operating frequency f2, the

conductor plates

10,30 can be made small and the

conductor plates

10,30 can be resonated at the second operating frequency f 2.

The first electrical length Le1 corresponds to a length that takes into account the shortest conductor length along the conductor plate 20 from the end 23 to the end 24, the dielectric constant and thickness of the base material in contact with or adjacent to the conductor plate 20, and the like. The second electrical length Le2 corresponds to a length obtained by considering the shortest conductor length along the

conductive plates

10 and 30 from the end 33 to the end 14 via the end 34, and the dielectric constant and thickness of the base material in contact with or adjacent to the

conductive plates

10 and 30.

Further, the opposing portion 31 of the conductor plate 30 and the plate surface 21 of the conductor plate 20 are preferably separated by an electrical length of a quarter wavelength of the first operating frequency f 1. Thus, the antenna device 101 is configured such that the plate surface 21 through which the current ib flows and the opposing portion 31 through which the current ic having the opposite phase to the current ib flows are grounded to the conductor plate 10 at a distance of a quarter wavelength. Thereby, the directivity of the antenna device 101 can be directed toward the end 14 side in the X-axis direction like an array antenna or a yagi antenna. The opposing portion 31 of the conductor plate 30, if parallel to the plate surface 21 of the conductor plate 20, may be directed toward the end 14 side in the X-axis direction, which is more preferable in this regard.

Further, the conductor plate 30 has an opposing portion 32 opposing the first plate surface portion 12 of the conductor plate 10. By providing the opposing portion 32, the directivity of the antenna device 101 is easily adjusted. The opposing portion 32 is more preferable in that the directivity is easily adjusted if it is parallel to the first plate surface portion 12 of the conductor plate 10. Further, by bending the conductor plate 30, the height of the antenna device 101 can be reduced as compared with a case where the conductor plate is not bent.

It is preferable that the plate surface 21 of the conductive plate 20 has a shape that is line-symmetric with respect to an imaginary line passing through the feeding portion 3 in the Z-axis direction, in that the directivity of the antenna device 101 can be made nearly symmetric with respect to the Z-axis direction. The conductor plate 20 has a plate surface 21 having, for example, a semicircular shape. However, the shape of the plate surface 21 is not limited to the semicircular shape, and may be other shapes such as an inverted triangle, a semi-ellipse, and the like. Further, a slit may be formed in the conductor plate 20.

As shown in the drawing, the conductor plate 20 can be bent such that the end portion 24 is closer to the end portion 33, thereby achieving a reduction in height of the antenna device 101. If the conductor length from the end 23 to the end 24 is 100mm or less, it is preferable to reduce the height of the antenna device 101, and more preferably 70mm or less.

The end 23 located at the bottom of the plate surface 21 is connected to the power supply unit 3. The end portion 23 may be connected to the power supply portion 3 in direct contact, or may be connected to the power supply portion 3 by capacitive coupling or the like.

It is preferable that the feeding portion 3 is located at the center of the conductive plate 10 in a direction parallel to the plate surface 21 (in fig. 1, the width direction of the plate surface 21 corresponding to the Y-axis direction), in that the directivity of the antenna device 101 is approximately symmetrical with respect to the normal direction of the plate surface 21 (in fig. 1, the X-axis direction). The central portion here means a range of ± 10% from the center of the width of the conductive plate 10 with reference to the width. The central portion is preferably within a range of ± 5% of the width, and more preferably the center of the width.

One end of the coaxial cable is directly connected to the power supply portion 3 by soldering or the like, or indirectly connected to the power supply portion 3 by a connector or the like. To the other end of the coaxial cable, for example, a device having at least one of a signal transmission function and a signal reception function is connected.

Fig. 2 is a diagram showing a first example of a power supply wire connected to a power supply unit. The power supply wire 6 connected to the power supply unit 3 includes a power transmission line 5 using the conductor plate 10 as a ground and a coaxial cable 4 connected to an end of the power transmission line 5. The power supply wire 6 is an example of a first power supply wire. The core wire 4a of the coaxial cable 4 is connected to the strip conductor 5a of the power transmission line 5, and is connected to the power feeding section 3 through the strip conductor 5 a. The outer conductor 4b of the coaxial cable 4 is connected to the conductor plate 10 functioning as a ground.

Specific examples of the power transmission line 5 include a microstrip line, a strip line, a coplanar waveguide having a ground plane (a coplanar waveguide in which a ground plane is disposed on a surface on the opposite side of a conductor surface on which a signal line can be formed), a coplanar strip line, and the like.

Fig. 3 is a diagram showing a second example of the power supply wire connected to the power supply unit. The power supply wire 6 connected to the power supply unit 3 includes the coaxial cable 4 connected to the power supply unit 3. The core wire 4a of the coaxial cable 4 is connected to the power supply portion 3. The outer conductor 4b of the coaxial cable 4 is connected to the conductor plate 10 functioning as a ground.

In fig. 1, the opposing portion 31 of the conductor plate 30 may have an opening 36. By providing the opening 36, the material of the opposing portion 31 can be reduced, and the weight of the antenna device 101 can be reduced. In the present embodiment, by providing the opening 36 in the opposing portion 31, the opposing portion 31 has

wall portions

31a,31b,31c surrounding the opening 36.

Wall portions

31a,31b are located on both sides of opening 36, wall portion 31a being connected to end 13 of conductor plate 10 at end 34a, and wall portion 31b being connected to end 13 of conductor plate 10 at end 34 b. Further, the wall portion 31c is connected to the meandering portion 35, and is connected to the wall portion 31a and the wall portion 31 b.

Further, the power supply wire connected to the power supply portion 3 can pass through the opening portion 36. Fig. 2 and 3 show examples in which the power supply wire 6 is inserted into the opening 36. Even when the opening 36 is not provided in the opposing portion 31, the high-frequency current is not easily passed through the central portion of the opposing portion 31, but easily passed along the outer edge of the opposing portion 31. Therefore, even if the opening 36 is provided in the center of the facing portion 31, the flow of the high-frequency current along the outer edge of the facing portion 31 is not easily blocked by the opening 36. Therefore, the impedance characteristics and radiation characteristics of the antenna device 101 are not easily affected by the provision of the opening 36. Further, if the power feeding wire 6 is passed through the opening 36 provided at the center of the opposing portion 31, the degree of coupling between the high-frequency current flowing along the outer edge of the opposing portion 31 and the high-frequency current in the vicinity of the power feeding wire 6 can be suppressed. Therefore, the impedance characteristic and radiation characteristic of the antenna device 101 are less likely to be affected by the high-frequency current near the power feeding wire 6 passing through the opening 36. For example, if the coaxial cable of the power feeding wire 6 does not pass through the opening 36 in the X-axis direction but passes across the side edge of the conductor plate 10 in the Y-axis direction, the high-frequency current flowing along the side edge is likely to be strongly coupled to the high-frequency current around the coaxial cable. This coupling may disturb the impedance characteristics and the radiation characteristics.

The power supply section 3 may be connected to the coaxial cable 4 through a matching circuit (matching circuit). This can further expand the frequency band that can be matched by the antenna device 101. Fig. 4 is a diagram showing an example of the configuration of the matching circuit. The matching circuit 40 is connected between the power supply section 3 and the port 7. The port 7 is connected to one end of a coaxial cable. The matching circuit 40 has capacitors 41 to 45 and inductors 46 to 49. The constants of the respective elements in the matching circuit 40 may be set as appropriate according to a desired frequency band to be matched.

The power supply section 3 may be connected to the coaxial cable 4 through a splitter. If a demultiplexer is provided, one antenna device 101 can be shared among a plurality of communication devices using different frequency bands. Fig. 5 is a diagram showing an example of the configuration of the demultiplexer. The splitter 50 is connected between the power supply section 3 and the

ports

8, 9. Port 8 is a terminal for extracting a radio wave on the low frequency side received by antenna device 101, and port 9 is a terminal for extracting a radio wave on the high frequency side received by antenna device 101. The port 8 is connected to one end of a coaxial cable for radio waves on the low frequency side, and is connected to a communication device for LTE, for example, via the coaxial cable. The port 9 is connected to one end of a coaxial cable for radio waves of a high frequency side, and is connected to a communication device for vehicle-to-vehicle communication or road-to-vehicle communication, for example, via the coaxial cable. The branching filter 50 includes a phase shifter 57, capacitors 51 to 53, and inductors 54 to 56. The phase shifter 57 is connected between the power supply unit 3 and the inductor 55. The constants of the respective elements in the demultiplexer 50 may be set as appropriate according to a desired frequency band to be matched.

In fig. 1, the antenna device 101 of the present embodiment may be configured such that the second antenna 60 is provided on the second plate surface portion 11 of the conductive plate 10. By inserting the power feeding wire 61 connected to the power feeding portion of the second antenna 60 through the opening portion 36, the influence of the high-frequency current in the vicinity of the power feeding wire 61 on the impedance characteristic and radiation characteristic of the antenna device 101 can be suppressed. A demultiplexer connected to the feeding portion 3 of the conductive plate 20 and the feeding portion of the second antenna 60 may be provided. Specific examples of the second antenna 60 include an antenna for a satellite positioning system such as a GPS.

Fig. 6 is a cross-sectional view schematically showing an example of the configuration of a vehicle window glass with an antenna device, and shows a cross-section on a plane perpendicular to the vehicle width direction. In fig. 6, the Y-axis direction indicates the vehicle width direction of the vehicle 80. Fig. 6 shows a case where the glass plate 70 is a windshield. The glass panel 70 is mounted to the window frame of the vehicle 80 at an angle θ relative to the horizontal plane 90. The angle θ is an angle (e.g., 30 °) larger than 0 ° and smaller than 90 °. By adjusting the length in the Y-axis direction of the glass plate 70, the directivity of the antenna device 101 can be adjusted for each vehicle type even if the angle θ of each vehicle type differs.

The vehicle window glass 100 includes a window glass plate 70 of the vehicle 80, and an antenna device 101 that can be mounted on the glass plate 70. The antenna device 101 is mounted on the glass plate 70 by a mounting member not shown.

At this time, at least one of the conductor plate 20 and the conductor plate 30 is brought close to the glass plate 70 by the distance D1, whereby the shortening effect by the glass plate 70 as a dielectric can be obtained, and the antenna device 101 can be downsized. Further, by bringing the conductor plate 10 close to the glass plate 70 by the distance D2, the shortening effect by the glass plate 70 as a dielectric can be obtained, and the antenna device 101 can be downsized.

The distance D1 represents the shortest distance between the

conductor plate

20 or 30 and the vehicle interior surface of the glass plate 70 (an example of the first distance). The distance D2 represents the shortest distance between the conductor plate 10 and the vehicle interior surface of the glass plate 70 (an example of the second distance). By making the distance D1 and the distance D2 different, the three-dimensional antenna device 101 having elements with Z-axis direction components can be formed.

The directivity of the planar antenna device having no Z-axis direction component is easily enhanced in the normal direction of the glass plate 70. In contrast, since the antenna device 101 of the present embodiment includes an element having a Z-axis direction component, the direction in which the directivity of the antenna device 101 is enhanced is inclined in a direction close to the horizontal plane 90 with respect to the normal direction of the glass plate 70. Therefore, according to the antenna device 101 of the present embodiment, since the directivity in the direction parallel to the horizontal plane 90 (horizontal direction) is improved, the antenna gain (operating gain) in the horizontal direction can be further increased.

The antenna device 101 of the present embodiment includes a curved element. When the antenna length is the same, the height of the element having a large number of bent portions can be reduced more easily than that of an antenna having no bent portion. By bending the element at two or more positions, the height (D2-D1) can be easily reduced while securing a predetermined antenna length. Therefore, the glass plate 70 can be prevented from protruding greatly from the surface on the vehicle interior side, and is less likely to be an obstacle for the passenger.

In the antenna device 101 of the present embodiment, the facing portion 32 of the conductive plate 30 and the second plate surface portion 11 of the conductive plate 10 are connected by strong capacitive coupling via the conductive plate 20 on which the plate surface 21 having the Z-axis direction component is formed. With such a connection, since the opposing portion 32 and the second plate portion 11 do not oppose each other or the opposing conductor portion is small (narrow), the capacitive coupling of the opposing portion 32 and the second plate portion 11 does not easily become strong. Therefore, according to the antenna device 101 of the present embodiment, good impedance matching can be obtained.

In addition, in order to improve the directivity in the horizontal direction, as shown in fig. 6, the distance D1 is preferably shorter than the distance D2. In addition, the distance D1 may be zero. When the distance D1 is zero, at least one of the conductor plate 20 and the conductor plate 30 is in contact with the vehicle interior surface of the glass plate 70.

In the embodiment shown in fig. 6, the antenna device 101 is disposed above the glass plate 70 on the vehicle interior side so that the facing portion 32 and the conductor plate 10 are parallel to the surface of the glass plate 70 on the vehicle interior side. The angle α represents an angle formed by the facing portion 32 and the plate surface 21, and the angle β represents an angle formed by the plate surface 21 and the conductor plate 10. The angle α is an angle greater than 0 ° and less than 180 ° (e.g., 90 °), and the angle β is also an angle greater than 0 ° and less than 180 ° (e.g., 90 °). The angles α and β are preferably right angles, but may be angles other than right angles (e.g., 45 °).

The facing portion 32 and the conductor plate 10 are not limited to being arranged in parallel with the surface of the glass plate 70 on the vehicle interior side, and may be arranged in non-parallel. Further, the angle α and the angle β may be the same angle or different angles.

The antenna device of the present embodiment is suitable for receiving and transmitting radio waves in the UHF (Ultra High Frequency) band and the SHF (Super High Frequency). For example, the antenna device is suitable for receiving and transmitting radio waves of 3 frequency bands (0.698GHz to 0.96GHz, 1.71GHz to 2.17GHz, 2.4GHz to 2.69GHz) among a plurality of frequency bands used by LTE (Long Term Evolution). Further, it is suitable for receiving and transmitting a radio wave of 5G (sub6) band.

The antenna device of the present embodiment is also suitable for receiving and transmitting radio waves in the ISM (industrial scientific medical) band. The ISM band includes 0.863 GHz-0.870 GHz (Europe), 0.902 GHz-0.928 GHz (USA), 2.4 GHz-2.5 GHz (world Wide band). As a communication standard using the 2.4GHz band which is one of ISM bands, there are wireless LAN (Local Area Network) based on the DSSS (Direct Sequence Spread Spectrum) system of ieee802.11b, Bluetooth (registered trademark), and partial FWA (fixed wireless Access) system.

Fig. 7 to 10 are diagrams showing an example of simulation results of the directivity of the antenna device 101 mounted on the windshield glass with respect to the radio wave of the vertical polarization wave as shown in fig. 6. Assume a case where the windshield is inclined 30 ° with respect to the horizontal plane.

Fig. 7 shows the antenna gain of the antenna device 101 measured at 3 frequencies f (0.698GHz,0.829GHz,0.960GHz) of the low frequency band in the vertical plane perpendicular to the horizontal plane. Fig. 8 shows the antenna gain measured at 3 frequencies f (0.698GHz,0.829GHz,0.960GHz) of the high frequency band of the antenna device 101 in the horizontal plane. Fig. 9 shows antenna gains measured at 3 frequencies f (1.71GHz,2.40GHz,2.69Hz) of the high frequency band of the antenna device 101 in a vertical plane perpendicular to the horizontal plane. Fig. 10 shows the antenna gain measured at 3 frequencies f (1.71GHz,2.40GHz,2.69GHz) in the high frequency band of the antenna device 101 in the horizontal plane.

The concentric circles shown in fig. 7 and 9 respectively indicate the front of the vehicle, the rear of the vehicle, the upper side of the vehicle, and the lower side of the vehicle when the antenna device located at the center of the concentric circle is viewed from the vehicle width direction. The concentric circles shown in fig. 8 and 10 indicate the front of the vehicle, the rear of the vehicle, the left of the vehicle, and the right of the vehicle, respectively, when the antenna device located at the center of the concentric circles is viewed from the top.

In fig. 7 to 10, the unit of antenna gain is dBi. As shown in fig. 7 to 10, the directivity can be imparted to the front of the vehicle in both the low frequency band and the high frequency band.

When the antenna gains shown in fig. 7 to 10 are measured, the dimensions of each part of the antenna device 101 shown in fig. 1 in mm are:

L2：4、

L11：95、

L12：40、

L21：19、

L22：5、

L31：20、

L32：30、

L33：40。

fig. 11 shows an example of the frequency characteristic of the standing wave ratio (VSWR) of the antenna device 101. As the characteristics of the antenna, the VSWR is preferably as close to 1 as possible. Although a sufficiently broad band can be achieved even when the power supply unit 3 is not connected to the matching circuit 40, the VSWR from 698MHz to 960MHz can be further reduced and a broad band can be further achieved by connecting the power supply unit 3 to the matching circuit 40.

In the measurement of the VSWR shown in fig. 11, the dimensions of the respective portions of the antenna device 101 shown in fig. 1 are the same as those in the measurement of the antenna gain shown in fig. 7 to 10.

Fig. 12 shows an example of frequency characteristics (699 to 7100MHz) of the average gain in the horizontal plane of the antenna device 101 for the horizontally polarized wave and the vertically polarized wave, respectively. In fig. 12, the vertical axis represents a value obtained by averaging antenna gains (operating gains) in respective horizontal directions of 0 ° to 360 ° parallel to the horizontal plane with respect to a radio wave receiving a horizontally polarized wave (or a vertically polarized wave). As shown in fig. 12, the antenna gain in the horizontal direction of the antenna device 101 is a sufficiently high value in transmitting and receiving a radio wave of a vertical polarization wave compared with a radio wave of a horizontal polarization wave. The horizontal antenna gain of the antenna device 101 is sufficiently high in transmitting and receiving radio waves of vertical polarization in a band from the LTE frequency band (0.698GHz to 0.96GHz) to the 5g (sub) frequency band (6 GHz).

Fig. 13 is a perspective view showing a first modification of the structure of the antenna according to the present embodiment. An antenna device 101A shown in fig. 13 is a first modification of the configuration of the antenna device 101. The antenna device 101A includes a second antenna 60A and a second feeding unit 62. The second antenna 60A is an example of the second antenna 60 described above. The configuration and effects of the antenna device 101A of the first modification are the same as those of the antenna device 101, and the description thereof will be omitted.

The second antenna 60A is provided on the end portion 14 side with respect to the plate surface 21. The feeding portion 62 is provided on the conductive plate 10 and is a feeding point for feeding power to the second antenna 60A. The power supply portion 62 is located between the end portion 14 and the power supply portion 3. With such a configuration, the antenna device 101A operates in a first operation mode in which the conductor plate 20 operates as a radiation element, a second operation mode in which the

conductor plates

10 and 30 operate as radiation elements, and a third operation mode in which the second antenna 60A operates as a radiation element. That is, 3 operation modes can be realized with one antenna device 101A. Since the second antenna 60A is provided on the end portion 14 side with respect to the plate surface 21, the space on the second plate surface portion 11 of the conductive plate 10 can be effectively used. Therefore, the antenna device 101A operating in a plurality of operation modes can be easily made compact.

The antenna device 101A includes a plurality of radiation elements for feeding power to the two different

power feeding units

3 and 62, and thus can be used as a MIMO (Multiple Input and Multiple Output) antenna or a diversity antenna.

Further, the radiation element (the

conductor plates

10,20,30) fed by the feeding portion 3 and the radiation element (the second antenna 60A) fed by the feeding portion 62 can be formed so as to be capable of transmitting and receiving radio waves of frequency bands overlapping each other.

Next, the structure of the antenna device 101A will be described in more detail.

The second antenna 60A is, for example, a conductor plate formed so as to be able to transmit and receive radio waves of a desired frequency band. The second antenna 60A may be formed to be able to transmit and receive radio waves of frequency bands (1.71 to 6GHz) including bands for LTE and 5G, for example, but may also be formed to be able to transmit and receive radio waves of frequency bands other than those.

The second antenna 60A has an end portion 63 connected to the feeding portion 62 and an end portion 64 located at a position distant from the conductor plate 10. The end portion 64 is located on the opposite side of the end portion 63, and more specifically, on the opposite side of the end portion 63 from the side where the conductor plate 10 is present. The end 63 and the end 64 are located away from each other in the Z-axis direction. From the viewpoint of securing a gain in a wide frequency band and securing horizontal plane symmetry of directivity, the feeding portion 62 is preferably provided within a range of ± 10% from the center of the width of the conductive plate 10, preferably within a range of ± 5% from the center of the width, and more preferably at the center of the width.

The second antenna 60A in fig. 13 has a plate surface 66, and the width of the plate surface 66 in a direction parallel to the conductive plate 10 (in the case of fig. 13, the X-axis direction) increases from the end 63 toward the end 64. When the feeding portion 62 is set as a fixed position on the conductive plate 10, the plate surface 66 of the second antenna 60A may face in either direction. Here, the direction parallel to the conductive plate 10 is not limited to the X-axis direction shown in fig. 13, and may be a direction inclined within a range of less than ± 90 ° with respect to the X-axis direction, for example, a Y-axis direction. The phrase "the plate surface 66 is enlarged from the end 63 toward the end 64" means that there may be a portion enlarged from the end 63 toward the end 64, and there may be a portion which continues with the same width or a portion which becomes narrower from the end 63 toward the end 64. Further, it is preferable that the plate surface 66 has no portion whose width is narrowed from the end 63 toward the end 64. The second antenna 60A may have a flat shape without being bent, but may have a three-dimensional shape with a bent portion as shown in the conductor plate 20. By providing the curved plate surface 66 in the second antenna 60A, the height of the antenna device 101A can be reduced as compared with a case where the second antenna is not curved. The height reduction described here corresponds to shortening the distance (height) in the Z-axis direction from the conductive plate 10.

Thus, in the antenna device 101A of the present embodiment, the second antenna 60A is connected to the feeding portion 62 at the end portion 63, and the width of the plate surface 66 is formed to increase as it goes away from the conductive plate 10. Therefore, by setting the length of the outer edge portion of the plate surface 66 (for example, the curved portion extending from the end portion 63) so that the second antenna 60A has an electrical length that operates in a desired frequency range, the second antenna 60A can be made to function as a radiation element of the UWB antenna.

It is preferable that the plate surface 66 of the second antenna 60A has a shape that is line-symmetric with respect to an imaginary line passing through the feeding portion 62 in the Z-axis direction, in that the directivity of the second antenna 60A can be made nearly symmetric with respect to the Z-axis direction. However, the shape of the plate surface 66 may not be line-symmetric. The second antenna 60A may have, for example, a substantially semicircular plate surface 66, or may have another shape such as an inverted triangle or a semi-ellipse. Further, a notch may be formed in the plate surface 66.

The second antenna 60A can be bent such that the end 64 approaches the end 63, as in the case of the conductor plate 20, thereby achieving a reduction in height of the antenna device 101A. The conductor length from the end 63 to the end 64 is preferably 100mm or less, more preferably 70mm or less, in view of reducing the height of the antenna device 101A.

The end 63 at the bottom of the plate surface 66 is connected to the power supply unit 62. End 63 may be connected to power feeding unit 62 in direct contact, or may be connected to power feeding unit 62 by capacitive coupling or the like.

The feeding portion 62 is grounded with the conductive plate 10 as a reference, for example. The power feeding portion 62 may be located on a virtual straight line passing through the power feeding portion 3 and parallel to the X-axis direction, or may be offset from the virtual straight line in the Y-axis direction.

Next, the position of the power supply unit 62 in the X axis direction will be described. Here, the shortest distance from end 14 to power feeding portion 3 is denoted as a, and the shortest distance from end 14 to power feeding portion 62 is denoted as B. In this case, the B/a is 0.15 or more and 0.40 or less, but is preferable in reducing the correlation coefficient between the radiation element (the

conductor plates

10,20,30) fed by the feeding portion 3 and the radiation element (the second antenna 60A) fed by the feeding portion 62. By reducing the correlation coefficient, interference between the radiation elements can be reduced. In order to reduce the correlation coefficient between the radiation elements, B/a is preferably 0.20 or more and 0.40 or less, more preferably 0.22 or more and 0.38 or less, and further preferably 0.24 or more and 0.36 or less. If B/A exceeds 0.40, the second antenna 60A comes too close to the conductive plate 20, and therefore interference between the conductive plate 10 and the second antenna 60A may increase. If B/a is less than 0.15, the second antenna 60A passes close to the end portion 14, and therefore, the flow of current along the end portion 14 is hindered, and there is a possibility that the antenna gain of the radiation element fed by the feeding portion 3 is lowered.

One end of the coaxial cable is directly connected to the power supply portion 62 by soldering or the like, or indirectly connected to the power supply portion 3 by a connector or the like. To the other end of the coaxial cable, for example, a device having at least one of a signal transmission function and a signal reception function is connected. The second power supply wire 61 (see fig. 1) connected to the power supply portion 62 may be in the same form as the power supply wire 6 (see fig. 2 and 3) connected to the power supply portion 3, or may be in a different form.

In fig. 13, in order to increase the antenna gain of the antenna device 101A, a configuration in which the second feeding wire 61 (see fig. 1) connected to the feeding portion 62 passes through the region between the feeding portion 62 and the end portion 14 is preferable to a configuration in which the second feeding wire passes through the region between the feeding portion 3 and the end portion 13. If the second power feeding wire 61 passes through the area between the power feeding portion 62 and the end portion 14, the flow of current along the end portion 14 may be hindered due to the presence of the second power feeding wire 61, and the antenna gain of the antenna device 101A may be lowered. That is, it is preferable that the second power feeding wire 61 does not pass through the region between the power feeding portion 62 and the end portion 14.

The second power supply wire 61 (see fig. 1) extends from the end 13 side toward the power supply portion 3, for example, and is connected to the power supply portion 62 through one side surface of the power supply portion 3 in the Y axis direction. The second power supply wire 61 may or may not have a portion extending along the power supply wire 6 connected to the power supply portion 3.

The second power supply wire 61 (see fig. 1) can pass through the opening 36. If the second power feeding wire 61 is passed through the opening 36 provided in the center of the opposing portion 31, the degree of coupling between the high-frequency current flowing along the outer edge of the opposing portion 31 and the high-frequency current in the vicinity of the second power feeding wire 61 can be suppressed. Therefore, the impedance characteristic and the radiation characteristic of the antenna device 101A are not easily affected by the high-frequency current near the second feeding wire 61 passing through the opening 36. For example, if the coaxial cable of the second power feeding wire 61 does not penetrate the opening 36 in the X axis direction but passes across the side edge of the conductor plate 10 in the Y axis direction, the high-frequency current flowing along the side edge is likely to be strongly coupled to the high-frequency current around the coaxial cable. This coupling may disturb the impedance characteristics and the radiation characteristics.

The power supply portion 62 may be connected to the coaxial cable through a matching circuit. Thereby, the frequency band that can be matched by the antenna device 101A including the second antenna 60A can be further expanded. The matching circuit connected to the power supply unit 62 may be the same as or different from the matching circuit 40 (see fig. 4) connected to the power supply unit 3.

The power supply portion 62 may be connected to the coaxial cable through a splitter. If a demultiplexer is provided, one antenna apparatus 101A can be shared among a plurality of communication apparatuses using different frequency bands. The branching filter connected to the power supply unit 62 may be of the same form as the branching filter 50 (see fig. 5) connected to the power supply unit 3, or may be of a different form.

Fig. 14 is a perspective view showing a second modification of the configuration of the antenna device of the present embodiment. An antenna device 101B shown in fig. 14 is a second modification of the structure of the antenna device 101. The antenna device 101B includes a second antenna 60B and

second feeding portions

62A and 62B. The second antenna 60B is an example of the second antenna 60 described above. The configuration and effects of the antenna device 101B of the second modification are the same as those of the

antenna devices

101 and 101A, and the description thereof is omitted.

The second antenna 60B may be configured by a plurality of antenna elements provided on the end portion 14 side with respect to the plate surface 21. In the case of fig. 14, the second antenna 60B is composed of a first antenna element 60Ba and a second antenna element 60 Bb. The feeding portion 62A is provided on the conductive plate 10 and feeds power to the first antenna element 60Ba, and the feeding portion 62B is provided on the conductive plate 10 and feeds power to the second antenna element 60 Bb. The

power feeding portions

62A,62B are each located at a position between the end portion 14 and the power feeding portion 3. With such a configuration, the antenna device 101B operates in a first operation mode in which the conductor plate 20 operates as a radiation element, a second operation mode in which the

conductor plates

10 and 30 operate as radiation elements, a third operation mode in which the first antenna element 60Ba operates as a radiation element, and a fourth operation mode in which the second antenna element 60Bb operates as a radiation element. That is, 4 operation modes can be realized with one antenna device 101B.

The first antenna 60Ba has an end 63A connected to the feeding portion 62A and an end 64A located at a position distant from the conductor plate 10. The second antenna 60Bb has an end 63B connected to the feeding portion 62B and an end 64B located at a position distant from the conductor plate 10.

The first antenna element 60Ba has a plate surface 66A, and the width of the plate surface 66A in a direction parallel to the conductive plate 10 (in the X-axis direction in fig. 14) increases from the end 63A toward the end 64A. The second antenna element 60Bb has a plate surface 66B, and the width of the plate surface 66B in a direction parallel to the conductive plate 10 (in the X-axis direction in fig. 14) increases from the end 63B toward the end 64B.

The first antenna element 60Ba has a substantially quarter-circle plate surface 66A, and the second antenna element 60Bb has a substantially quarter-circle plate surface 66B. However, the shape of the plate surfaces 66A,66B is not limited to the approximately quarter-circle shape, and may be other shapes such as a semicircle, an inverted triangle, or a half ellipse. Further, a notch may be formed in the plate surfaces 66A, 66B. By forming the plate surfaces 66A,66B into a shape such as a substantially quarter circle having an area smaller than that of a semicircle, interference between antennas can be reduced even if an antenna for a satellite positioning system or the like is further installed between the plate surfaces 66A, 66B.

Next, the positions of the

power feeding portions

62A,62B in the X axis direction will be described. Here, the shortest distance from end 14 to power feeding portion 3 is denoted as a, and the shortest distance from end 14 to power feeding portion 62A is denoted as B. In this case, the B/a is 0.15 or more and 0.40 or less, but it is preferable to reduce the correlation coefficient between the radiation element (the

conductor plates

10,20,30) fed by the feeding portion 3 and the radiation element (the first antenna 60Ba) fed by the feeding portion 62A. The same applies to the shortest distance B from the end portion 14 to the feeding portion 62B. The shortest distance from end 14 to feeding portion 62A may be the same as or different from the shortest distance from end 14 to feeding portion 62B.

Fig. 15 is a perspective view showing a third modification of the structure of the antenna device of the present embodiment. An antenna device 101C shown in fig. 15 is a third modification of the structure of the antenna device 101. The antenna device 101C includes a second antenna 60C and a feeding unit 62. The second antenna 60C is an example of the second antenna 60 described above. The configuration and effects of the antenna device 101C of the third modification are the same as those of the antenna devices 101,101A, and 101B, and the description thereof is omitted.

In the second antenna 60C, the first antenna element 60Ba and the second antenna element 60Bb are fed by the common feeding portion 62. For example, the feeding portion 62 is connected to the end 63A of the first antenna element 60Ba via the conductor 65, and connected to the end 63B of the second antenna element 60Bb via the conductor 65. The second antenna 60C can be widened by feeding the first antenna element 60Ba and the second antenna element 60Bb through the common feeding portion 62.

Fig. 16 is a perspective view showing a fourth modification of the configuration of the antenna device of the present embodiment. An antenna device 101D shown in fig. 16 is a fourth modification of the configuration of the antenna device 101. The antenna device 101D includes a second antenna 60D and a feeding unit 62. The second antenna 60D is an example of the second antenna 60 described above. The configuration and effects of the antenna device 101D of the fourth modification are the same as those of the antenna devices 101,101A,101B, and 101C, and the above description is applied, and the description thereof is omitted.

The second antenna 60D is a slot antenna provided on the end portion 14 side with respect to the board surface 21. The feeding portion 62 is provided on the conductive plate 10 and is a feeding point for feeding power to the second antenna 60D. The power supply portion 62 is located between the end portion 14 and the power supply portion 3. The second antenna 60D has a notch whose width in a direction parallel to the conductor plate 10 (Y-axis direction in fig. 16) increases from the feeding portion 62 toward the end portion 14. The undercut may be a void or may be filled with a dielectric.

The conductive plate 20 fed by the feeding unit 3 is a vertical polarized wave antenna, whereas the second antenna 60D is a horizontal polarized wave antenna, and therefore the degree of mutual interference between the two antennas is small. Therefore, in the antenna device 101D, even if a/B exceeds 0.40, the degree of reduction in antenna gain is small compared to the antenna device 101A, and therefore the position of the feeding portion 62 in the X axis direction can be arbitrarily determined. In view of securing a gain in a wide frequency band and securing horizontal plane symmetry of directivity, feeding unit 62 is preferably provided within a range of ± 10% from the center of the width of conductive plate 10, preferably within a range of ± 5% from the center of the width, and more preferably at the center of the width. The width of the cut groove is smaller than the width of the conductive plate 10, and the end portion 14 of the conductive plate 10 is provided on both sides of the cut groove in the Y-axis direction. This is because, as described above, the high-frequency current is not easily passed through the central portion of the facing portion 31, but easily passed along the outer edge of the facing portion 31, so as not to interfere with the electrical operation of the current ia passed through the

conductive plates

10 and 30 in the second operation mode.

Fig. 17 shows an example of the frequency characteristic of the standing wave ratio (VSWR) of the antenna device 101A. As the characteristics of the antenna, the VSWR is preferably as close to 1 as possible. Fig. 17 shows a case where the matching circuit is connected to any one of the power supply portion 3 and the power supply portion 62. As shown in fig. 17, in the frequency bands for LTE and 5G (1.7GHz to 6GHz), both the radiation elements (

conductor plates

10,20,30) fed by the feeding unit 3 and the radiation element (second antenna 60A) fed by the feeding unit 62 can be broadband.

Fig. 18 shows the antenna gain measured at 5.9GHz of the antenna device 101A disposed near the windshield glass of the vehicle in the horizontal plane. The concentric circles shown in fig. 18 indicate the front of the vehicle, the rear of the vehicle, the left of the vehicle, and the right of the vehicle when the antenna device located at the center of the concentric circles is viewed from the top, and the right, the left, and the upper sides, and the lower sides, respectively.

In fig. 18, the unit of antenna gain is dBi. As shown in fig. 18, by providing the antenna device 101A in the vicinity of the windshield glass of the vehicle, a radiation pattern having a plurality of modes with directivity toward the front of the vehicle can be formed. Therefore, by providing the same antenna device 101A also in the vicinity of the rear side glass of the vehicle, the radiation pattern can be made to approach nondirectivity.

Fig. 19 is a graph showing correlation coefficients in the antenna device 101A. The correlation coefficient shown in fig. 19 represents an Envelope Correlation Coefficient (ECC) between the radiation element (the

conductor plates

10,20,30) fed by the feeding portion 3 and the radiation element (the second antenna 60A) fed by the feeding portion 62. As shown in fig. 19, in the frequency bands for LTE and 5G (1.7GHz to 6GHz), the correlation coefficient between the two radiation elements is about 0.3 or less, and therefore the degree of mutual interference between the two radiation elements is small. Therefore, the antenna device 101A can be used as a MIMO antenna.

In the measurement of the data shown in fig. 17 to 19, the dimensions of the respective portions of the antenna device 101A shown in fig. 13 in mm are:

L2：4、

L11：95、

L12：40、

L21：19、

L22：5、

L31：20、

L32：30、

L33：40、

L60：15、

L61：19、

A：50、

B：15。

the radius of curvature of the curved portion of the plate surface 66 that diverges from the end 63 is 8 mm.

Although the antenna device and the vehicle window glass have been described above with reference to the embodiments, the present invention is not limited to the embodiments. Various modifications and improvements such as combinations and substitutions of a part or all of the other embodiments are possible within the scope of the present invention.

As a window glass to which the present invention is applicable, for example, a front window glass mounted on a front portion of a vehicle can be cited. However, the window glass may be a rear window glass mounted on the rear portion of the vehicle or a side window glass mounted on the side portion of the vehicle.

Although the glass plate is shown in the above-described embodiment as an example of the substrate on which the antenna device can be mounted, the substrate is not limited to the glass plate and may be another member. The substrate may also cover the antenna device. The antenna device may be mounted on the glass plate by means of a substrate. The material of the substrate is preferably a dielectric.

The shape of the portion constituting the antenna conductor is not limited to a linearly extending shape, and may be a shape extending with an arc and a curve. The shape of the corner portion of the antenna conductor is not limited to a right angle, and may be an arc shape with a circular arc.

The conductor plate is not limited to a simple flat plate, and may be curved. Each of the conductive plates may be formed by connecting two or more conductive plates.

Further, the antenna device of the present embodiment may be mounted on an upper region of a central portion of the front window in the vehicle width direction, or may be mounted on an upper region of a central portion of the rear window in the vehicle width direction.

Further, a plurality of antenna devices according to the present embodiment may be mounted on the windshield glass (preferably, on the upper region of the windshield glass in the vehicle width direction) with a space therebetween in the vehicle width direction. Thus, interference between the antenna devices is reduced by securing a certain distance between the antenna devices, and thus an antenna system corresponding to MIMO (Multiple Input and Multiple output) can be provided. In addition, it can be used as a diversity antenna. The same applies to the case where a plurality of antenna devices of the present embodiment are mounted on a rear window (preferably, an upper region of the rear window in the vehicle width direction) with a space therebetween in the vehicle width direction.

Further, at least one antenna device of the present embodiment may be mounted on each of the front window and the rear window. That is, it is possible to provide a window glass structure including a vehicle windshield glass, a vehicle rear window glass, and the antenna device of the present embodiment mounted on at least one of the windshield glass and the rear window glass. With such a window glass structure, directivity can be supplemented in the vehicle front-rear direction, and the performance of transmitting and receiving signals as an antenna system can be improved. Further, since a certain distance can be secured between the antenna devices, interference between the antenna devices is reduced, and an antenna system compatible with MIMO (for example, 4 × 4MIMO) can be provided.

Further, it is also possible to provide an antenna system including at least one antenna device of the present embodiment mounted on a windshield glass and at least one antenna device of a type different from that of the antenna device. Specific examples of the different types of antenna devices in this case include a shark fin antenna, a spoiler-embedded antenna, an antenna provided in a rear tray portion, a rearview-mirror-embedded antenna, and an antenna formed on a side window glass portion.

Similarly, an antenna system including at least one antenna device of the present embodiment mounted on a rear window and at least one antenna device of a different type from the antenna device can also be provided. Specific examples of the different types of antenna devices in this case include an antenna built in an instrument panel, an antenna built in a fender, an antenna built in a side mirror, and an antenna formed on a side window glass portion.

By combining at least one of these different types of antenna devices with at least one of the antenna devices of the present embodiment mounted on a windshield glass or a rear window, an antenna system corresponding to MIMO (e.g., 4 × 4MIMO) can be provided.

The international application claims priority based on japanese patent application No. 2018-.

Description of the symbols

3 power supply part

4 coaxial cable

5 electric transmission line

6 power supply wire

7-9 port

10 conductive plate (an example of the first conductive plate)

13 end (an example of the first end)

14 end portion (an example of the second end portion)

20 conductive plate (an example of the second conductive plate)

21 plate surface

23 end (an example of the third end)

24 end portion (an example of the fourth end portion)

30 conductive plate (an example of the third conductive plate)

31 opposite part

32 opposite part (an example of the second opposite part)

33 end portion (an example of the fifth end portion)

34 end portion (an example of the sixth end portion)

40 matching circuit

50 wave separator

60,60A,60B,60C,60D second antenna

61 second power supply wire

62 power supply part

66 plate surface

70 glass plate

80 vehicle

90 horizontal plane

100 window glass for vehicle

101,101A,101B,101C,101D antenna arrangement.

Claims

1. An antenna device comprising a first conductive plate, a second conductive plate and a third conductive plate,

the first conductor plate has a first end portion and a second end portion on the opposite side of the first end portion, and a first feeding portion is provided between the first end portion and the second end portion;

the second conductive plate has a third end connected to the first feeding portion, a fourth end located at a position distant from the first conductive plate, and a plate surface whose width in a direction parallel to the first conductive plate increases from the third end toward the fourth end;

2. The antenna device of claim 1, wherein the second conductor plate has a first electrical length that resonates at a first operating frequency;

the first and third conductive plates have a second electrical length that resonates at a second operating frequency that is lower than the first operating frequency.

3. The antenna arrangement according to claim 2, wherein the first electrical length is a quarter wavelength of the first operating frequency.

4. An antenna arrangement according to claim 2 or 3, wherein the second electrical length is a quarter wavelength of the second operating frequency.

5. An antenna device according to any of claims 2 to 4, wherein the opposing portion and the panel face are separated by an electrical length of a quarter wavelength of the first operating frequency.

6. The antenna device according to any one of claims 1 to 5, wherein the opposing portion is parallel to the plate surface.

7. The antenna device according to any one of claims 1 to 6, wherein the opposing portion has an opening portion.

8. The antenna device according to claim 7, wherein a first feeding wire connected to the first feeding portion passes through the opening portion.

9. The antenna device according to any one of claims 1 to 8, wherein the third conductor plate has a second opposing portion facing the first conductor plate.

10. The antenna device according to claim 9, wherein the second opposing portion is parallel to the first conductor plate.

11. The antenna device according to any one of claims 1 to 10, wherein the shape of the plate surface is line-symmetric with respect to an imaginary line passing through the first feeding portion.

12. The antenna device according to any one of claims 1 to 11, wherein the plate surface has a semicircular shape.

13. The antenna device according to any one of claims 1 to 12, wherein the second conductor plate is bent such that the fourth end portion is close to the fifth end portion.

14. The antenna device according to any one of claims 1 to 13, wherein a conductor length from the third end portion to the fourth end portion is 100mm or less.

15. The antenna device according to any one of claims 1 to 14, wherein the first feeding portion is located at a central portion of the first conductive plate in a direction parallel to the plate surface.

16. The antenna device according to any one of claims 1 to 15, wherein the first feeding portion is connected to a coaxial cable through a matching circuit.

17. The antenna device according to any one of claims 1 to 16, wherein the first feeding portion is connected to a coaxial cable through a splitter.

18. The antenna device according to any one of claims 1 to 17, comprising an antenna provided on the second end portion side with respect to the plate surface, and a second feeding portion provided on the first conductive plate and feeding power to the antenna, wherein the second feeding portion is located between the second end portion and the first feeding portion.

19. The antenna device according to claim 18, wherein when a shortest distance from the second end to the second feeding portion is denoted by a and a shortest distance from the second end to the second feeding portion is denoted by B, B/a is 0.15 or more and 0.40 or less.

20. The antenna device according to claim 18 or 19, wherein the antenna has a plate surface whose width in a direction parallel to the first conductive plate is enlarged as it is farther from the first conductive plate.

21. The antenna device according to any one of claims 18 to 20, wherein a second feeding wire connected to the second feeding portion passes through a region between the second feeding portion and the first end portion.

22. A window glass for a vehicle, comprising a window glass plate for a vehicle, and at least one antenna device according to any one of claims 1 to 21 attached to the glass plate.

23. A window glass structure comprising a vehicle windshield glass, a vehicle rear window glass, and at least one antenna device according to any one of claims 1 to 21 attached to each of the windshield glass and the rear window glass.